96 GMC Jimmy P0108

[Tstown]

Need help. Recently received a code of p0108 - Map sensor high input voltage. The vehicle does not shift into passing gear when throttle is mashed and receiving major spark knock.
So far we have:
- checked timing set at -1 degrees
- installed new map sensor
- Recently have had the transmission rebuilt, shift problemn may not be related.

Any ideas where to check next? What would give the map sensor a high voltage input error.

[BlazerLT]

Originally Posted by Tstown

Need help. Recently received a code of p0108 - Map sensor high input voltage. The vehicle does not shift into passing gear when throttle is mashed and receiving major spark knock.
So far we have:
- checked timing set at -1 degrees
- installed new map sensor
- Recently have had the transmission rebuilt, shift problemn may not be related.

Any ideas where to check next? What would give the map sensor a high voltage input error.

Did the check engine light come back on?

[Tstown]

Yes, the check engine light comes back. Same code. Any ideas at all?

[BlazerLT]

With MAP sensor replaced, I would have to think you might have a Computer problem.

The shifting thing is not related, but why haven't you taken it back to the guys that rebuilt it?

[Tstown]

Thanks for the reply. He believes there may be a short in the computer that is affecting the shifting problem also. He is checking on a kit made by GM to fix the tranny problem. We were not sure whether the map sensor code problem could affect the electronics for the tranny. Ever heard of the a kit for that? Maybe a new computer? Any ideas on costs associated with getting a new computer?
Again thanks for any input.

[Tstown]

Forgot to mention, that tranny guy believes that the downshift problem probably burned up the tranny. He could not find anything inside that would have. Just thought I would mention.

[BlazerLT]

Watch it, it sounds like they are going to blame it all on the MAP sensor.

Transmission will not be affected by a MAP error like that.